Display shape and orientation for debugging

src/bin/tetris/main.rs

@@ -16,7 +16,7 @@ fn main() {
             ..default()
         })
         .init_state::<Falling>()
-        .add_systems(Startup, init_pieces)
+        .add_systems(Startup, (init_pieces, init_debug_ui))
         .add_systems(
             Update,
             (
@@ -35,6 +35,8 @@ fn main() {
                     any_component_added::<RelativePosition>
                         .or(any_component_changed::<RelativePosition>),
                 ),
+                sync_singleton_to_ui::<Shape>.run_if(any_component_changed::<Shape>),
+                sync_singleton_to_ui::<Orientation>.run_if(any_component_changed::<Orientation>),
             ),
         )
         .add_systems(Update, draw_grid)
@@ -44,8 +46,9 @@ fn main() {
 const SCALE: f32 = 30.0;
 
 /// A shape, e.g., the long piece
-#[derive(Component, Debug)]
+#[derive(Component, Debug, Default)]
 enum Shape {
+    #[default]
     O,
     T,
     L,
@@ -55,6 +58,20 @@ enum Shape {
     I,
 }
 
+impl Display for Shape {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Shape::O => write!(f, "O"),
+            Shape::T => write!(f, "T"),
+            Shape::L => write!(f, "L"),
+            Shape::J => write!(f, "J"),
+            Shape::S => write!(f, "S"),
+            Shape::Z => write!(f, "Z"),
+            Shape::I => write!(f, "I"),
+        }
+    }
+}
+
 /// A part of a piece, i.e., a single square of a piece
 #[derive(Component, Debug)]
 struct ShapePiece;
@@ -189,6 +206,17 @@ impl Orientation {
     }
 }
 
+impl Display for Orientation {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Orientation::Up    => write!(f, "up"),
+            Orientation::Down  => write!(f, "down"),
+            Orientation::Left  => write!(f, "<-"),
+            Orientation::Right => write!(f, "->"),
+        }
+    }
+}
+
 #[derive(States, Clone, Eq, PartialEq, Debug, Hash, Default, Component)]
 enum Falling {
     #[default]
@@ -218,13 +246,31 @@ fn init_pieces(
     commands.spawn((Orientation::default(), GridPosition::default(), Shape::T));
 }
 
+fn init_debug_ui(
+    mut commands: Commands,
+) {
+    commands.spawn((Node {
+        top: Val::Px(0.0),
+        left: Val::Px(0.0),
+        ..default()
+    }, DebuggingState::On)).with_children(|parent| {
+        parent.spawn((
+            Node::default(),
+            children![
+                (Text::new("SHAPE"), SyncSingleton::<Shape>::default()),
+                (Text::new("ORIENTATION"), SyncSingleton::<Orientation>::default()),
+            ]
+        ));
+    });
+}
+
 fn set_piece(
     query: Query<(Entity, &Shape, &Orientation), Or<(Added<Shape>, Changed<Shape>, Added<Orientation>, Changed<Orientation>)>>,
     mut commands: Commands,
     visuals: Res<Visuals>,
 ) {
     query.iter().for_each(|(e, s, o)| {
-        info!("{e:?} {s:?} {o:?}");
+        debug!("{e:?} {s:?} {o:?}");
         commands
             .entity(e)
             .despawn_related::<Children>()

src/ui.rs

@@ -175,6 +175,23 @@ pub fn sync_resource_to_ui<R: Resource + Default + Display>(
     });
 }
 
+/// Marker component for handling Resource -> Ui Sync
+#[derive(Component, Default, Debug)]
+pub struct SyncSingleton<C: Component + Default + Display>(C);
+
+/// Sync a singleton entity's component to the UI
+///
+/// Mostly useful for quick n' dirty getting data to the user
+pub fn sync_singleton_to_ui<C: Component + Default + Display>(
+    mut q: Query<(&mut Text, &mut Visibility), With<SyncSingleton<C>>>,
+    c: Single<&C>,
+) {
+    q.iter_mut().for_each(|(mut t, mut v)| {
+        t.0 = format!("{}", *c);
+        *v = Visibility::Inherited;
+    });
+}
+
 /// Updates the scroll position of scrollable nodes in response to mouse input
 pub fn scroll(trigger: Trigger<Pointer<Scroll>>, mut scrollers: Query<&mut ScrollPosition>) {
     let Pointer {